To put it into perspective... high end 1080p monitors for many are already prohibitively expensive... this kind of consumer won't likely take the risk on low end 1440p or above especially because proper upcsaling would require higher end CPU's which would necessitate even more upgrades. At 1080p the CPU only affects rendering because upscaling to 1080p barely does anything which is why the benchmarks show the discrepancies they do.Don't know what you consider expensive but 1440p and even 4k monitors aren't that bad. GPU's to make best use of them can be. It sounds like you live in a place where higher end hardware is very expensive, and I am sorry if that is true.
Typically the pattern seems to be that a consumer can afford a GPU and monitor at the same price.... but he is more likely to spend three times more for a GPU because getting the game running well is more important than getting it displaying well. Many people also upgrade their GPU's three or more times as quickly as they do their monitors.
It's not only the monitor cost you have to take into account, it's a matter of stepping up to the next tier. For many getting a 1440p monitor means he has to basically upgrade everything and this is even more true for 4k where a high end CPU and perhaps faster RAM is basically essential where you might have been able to plod along at 1440p. But that said.... for many monitors are much more expensive than they are for others. Even as much as tarrifs are inflating tech prices in the US tied economies now they are still far cheaper than they are elsewhere.
Think of it yet another way.... if you save up all year and you can only afford to upgrade one component upgrade every 2nd or 3rd year if at all.... how will that affect your spending?
Where I live the price someone in the US used to pay (who knows atm due to the fluctuations) basically doubles or tripples for the same thing by the time it gets to me... which of course means that China dominates all tech markets.